The invention relates to a lock cylinder, in particular for mortise locks with mechanically operating tumbler pins controlled by the key and at least one electromagnetic tumbler which is arranged in the cylinder casing and comprises a coil as well as a locking member, which can be moved by electromagnetic forces, for an additional tumbler pin spring-loaded in the locking direction and with a reading device detecting a key code.
A lock cylinder of this type is known from European Patent Application 0 281 507, the tumbler pin spring-loaded in the engagement direction engaging with its conical head into a half dish in the cylinder core. The end of the tumbler pin opposite the head co-operates with spreading spheres which are located in casing bores and are in turn surrounded by a tubular locking member. This tubular locking member is provided with an armature which is coaxially orientated relative to the tumbler pin and sinks against spring loading into a coil. If an incorrectly coded key is inserted into the lock cylinder, this is registered by the reading device and the coil connects to the electric circuit, so that the locking member is displaced relative to the tumbler pin and the spheres and removes their freedom of radial movement. Closing rotation is therefore checked as the tumbler pin cannot escape. In addition to the disadvantage that the lock contains a large number of parts, the design cannot withstand high loads. Furthermore, the locking member always has to move against spring loading, requiring greater energy which has proven to be disadvantageous, particularly when the electromagnetic tumbler is powered by a battery.
It is an object of the present invention to provide a lock cylinder of this type in which the electromagnetic tumbler produces locking which can withstand high loading locking while having a compact construction and using minimal electrical power for control thereof.